1. Field of the Invention
The present invention relates to an endoscope insertion shape observation probe that generates magnetism to be received by an endoscope insertion shape observation apparatus which captures an insertion state of an insertion portion.
2. Description of the Related Art
In a recent colonoscopy which requires advanced technique, an endoscope insertion shape observation apparatus (UPD/Endoscope Position Detecting Unit) that three-dimensionally displays an insertion shape of an insertion portion of an endoscope on a monitor using a magnetic field is known. The UPD does not expose patients to radiation, in contrast to the method of checking an insertion shape using the conventional X-ray photography, and therefore, the examination using the UPD is known as a more effective examination for patients.
When the UPD is used, it is necessary to use an endoscope including, in an insertion portion thereof, a probe incorporating a plurality of magnetic coils, or to insert a dedicated probe having a plurality of magnetic coils in a treatment instrument channel of the endoscope. The magnetism transmitted from the plurality of magnetic coils is received by an antenna arranged at the center of a UPD main body. The UPD connects the positions of the respective magnetic coils obtained by three-dimensionally capturing the received positions of the coils, with a smooth curve, and further performs graphics processing so as to make it easier to view the shape of the insertion portion to display the insertion portion on the monitor.
Regarding the magnetic coil used in such a UPD, for example, Japanese Patent Application Laid-Open Publication No. 7-111969 discloses a technique for covering a part of a connection copper wire connected to a copper wire of the coil with an insulation material and forming an outer surface of the insulation material to be a curved surface, thereby preventing mutual breakage of the internal components of an endoscope and the coil due to interference therebetween caused by bending operation, insertion operation, etc. Regarding the conventional coil, a technique for disposing the coil with the direction thereof reversed is disclosed, in order to improve the bending resistance of the coil, when the coil is incorporated into an endoscope.
In addition, for example, Japanese Patent Application Laid-Open Publication No. 2007-142151 discloses a technique for reducing the size of the coil device and improving assembly thereof by integrally forming an external connection terminal at an end portion of an iron core on which the coil is wound.